LTP Allergy Follow-Up Study: Development of Allergy to New Plant Foods 10 Years Later.

INTRODUCTION: Allergy to nonspecific lipid transfer protein (nsLTP) is the main cause of plant-food allergy in Spain. nsLTPs are widely distributed in the plant kingdom and have high cross-reactivity but extremely variable clinical expression. Little is known about the natural evolution of this allergy, which complicates management. The objective of this study was to assess the development of allergy to new plant foods in nsLTP-sensitized patients 10 years after diagnosis. METHODS: One hundred fifty-one patients showing specific IgE to nsLTP determined by ISAC (Thermofisher) were included. After clinical workup (i.e., anamnesis, skin test, and challenge when needed), these patients were divided into two groups: 113 patients allergic to one or more plant food (74.5%) and 38 patients not allergic to any plant food (25.1%). Ten years later, a telephone interview was conducted to check whether patients had developed additional allergic reactions to plant foods. RESULTS: Ten years after diagnosis, 35 of the 113 (31%) plant-food-allergic patients sensitized to nsLTP reported reactions to new, previously tolerated plant foods, mainly Rosaceae/Prunoideae fruits and nuts followed by vegetables, Rosacea/Pomoideae fruits, legumes, and cereals. Five out of 38 (13.2%) patients previously sensitized to nsLTP but without allergy to any plant food had experienced allergic reactions to some plant food: two to Rosaceae/Prunoideae fruits, two to Rosaceae/Prunoideae fruit and nuts, and one to legumes. CONCLUSION: Patients sensitized to nsLTP developed allergic reactions to other plant foods, mainly Rosaceae-Prunoideae fruits and nuts. This was more frequent among plant-food-allergic patients than among those who had never had plant-food allergy.

Pollen-food allergy syndrome and component sensitization in adolescents: A Japanese population-based study.

Allergic rhino-conjunctivitis with pollen allergy has been prevalent worldwide and Pollen-food allergy syndrome (PFAS) refers to individuals with pollen allergy who develop oral allergy syndrome (OAS) on consuming fruits and vegetables. The prevalence of PFAS varies by region and that in Japanese adolescents remains to be elucidated. In this cross-sectional study, we examined the epidemiological characteristics of PFAS in a general population of Japanese adolescents according to pollen allergy, OAS, and IgE component sensitization. Participants comprised adolescents, at age 13 years, from a prospective birth cohort study in Japan. We administered questionnaires to collect information from parents regarding pollen allergy, PFAS and OAS at each child's age 13 years. ImmunoCAP ISAC was used to assess IgE component sensitization. Among 506 participants with a complete questionnaire and ISAC measurement results, 56.5% had a history of hay fever, 16.0% had a history of OAS, 51.0% had pollen allergy, and 11.7% had a history of PFAS; additionally, 72.7% were sensitized to one or more tree, grass, and/or weed allergens. The most common sensitization (95.7%) among adolescents with pollen allergy was to Japanese cedar (Cry j 1). The most common causal foods were kiwi and pineapple (both 39.0%). Knowledge levels about PFAS were poor among affected adolescents. We found a high prevalence of PFAS among adolescents in Japan. Although it affects approximately 1/10 adolescents in the general population, public awareness regarding PFAS is poor. Interventional strategies are needed to increase knowledge and to prevent PFAS in the general population.

Oral allergy syndrome by fruit and vegetable PR-10 allergy: Accuracy of in vivo diagnosis.

Routine diagnostic methods for allergies to plant-derived foods are based on skin prick test (SPT) with commercial extracts, prick-by-prick (PbP) with fresh food, serum-specific IgE measurement, and oral food challenge.We discuss the possibility and the advantages of performing, in patients with oral allergy syndrome (OAS) by fruit and vegetables (excluding nuts) PR-10 allergy, component-resolved diagnosis (CRD) by SPT and PbP with raw and cooked vegetables, rather than performing a CRD with in vitro tests by drawing blood.Based on our clinical experience and the studies published in the literature, we believe that, at least for the OAS by fruit and vegetables (excluding nuts) PR-10 allergy, the search for sensitizing allergens and related cross-reactive allergens with SPT and PbP can be performed routinely in clinical practice, even at the primary-care level.

Potential of microbial endophytes to enhance the resistance to postharvest diseases of fruit and vegetables.

Food loss of fruit and vegetables caused by postharvest diseases is a major issue worldwide. The method used to prevent and control postharvest diseases is usually to use chemical fungicides, but long-term and large-scale use will make the pathogens resistant and potentially have a negative impact on human health and the ecological environment. Therefore, finding a safe and effective biological control method instead of chemical control is a hot research topic in recent years. Endophytes, colonizing plants asymptomatically, can promote the growth of the hosts and enhance their resistance. The use of endophytes as biological control agents for postharvest diseases of fruit and vegetables has attracted increasing attention in the last 20 years. Compared with chemical control, endophytes have the advantages of being more environmentally friendly, sustainable, and safer. However, there are relatively few relevant studies, so herein we summarize the available literature. This review focuses mainly on the recent progress of using endophytes to enhance the resistance of postharvest fruit and vegetables to diseases, with the emphasis on the possible mechanisms and the potential applications. Furthermore, this article suggests future areas for study using antagonistic endophytes to prevent and control fruit and vegetable postharvest diseases: (i) screening more potential broad-spectrum anti-pathogen endophytes and their metabolic active substances by the method of macrogenomics; (ii) elucidating the underlining molecular mechanism among endophytes, harvested vegetables and fruit, pathogens, and microbial communities; (iii) needing more application research to overcome the difficulties of commercialization practice. © 2020 Society of Chemical Industry.

Application of commercial kits using DNA-based and immunochemical methods for determination of shrimp allergens in kimchi and its ingredients.

Shrimps cause a significant part of crustacea-related allergies. It is used in processed foods, including fermented Korean foods, such as kimchi. Even low amounts of shrimp allergens can provoke reactions in consumers allergic to shrimp. Accurate food labeling is the most effective means of preventing the consumption of allergenic ingredients. To validate labeling compliance and minimize the risk of cross-contaminations, the effectiveness of methodologies used for the detection of allergens in foods should be compared. Here, seven commercial kits, based on quantitative real-time polymerase chain reaction (PCR) or enzyme-linked immunosorbent assay (ELISA), were assessed for their ability to detect the presence of shrimp allergens in food. Our results showed that SureFood real-time PCR kit and Ridascreen ELISA kit had the highest recovery, whereas five other kits underperformed in the determination of allergen content of kimchi and its ingredients. The variation in recovery among the kits depended on the limit of detection and reactivity to the shrimp allergens, tropomyosin, and sarcoplasmic calcium-binding protein. PRACTICAL APPLICATION: This research confirms the performance of commercial kits to detect the presence of shrimp allergens in kimchi, and demonstrates that the sensitivity of these kits depends on reactivity to the specific shrimp allergenic proteins. These results can be used to food allergy labeling and can be applied by the food industry to develop allergen test kits for fermented foods with improved performance.

Can patients with oral allergy syndrome be at risk of anaphylaxis?

PURPOSE OF REVIEW: Oral allergy syndrome, also known as pollen-food syndrome (PFS), is a condition usually associated with adults and characterized by mild transient oropharyngeal symptoms. The purpose of this review is to determine whether systemic or anaphylactic reactions do occur and if so, who is affected and what are the triggers. RECENT FINDINGS: An increasing number of studies demonstrate that PFS occurs all age groups, and a significant number of affected adults do experience systemic and anaphylactic reactions. The upsurge in the adoption of vegan lifestyles, increase in consumption of fruits and vegetables including smoothies and juices, and use of plant foods in nutritional or body-building supplements, could exacerbate this. Changes in pollen and pollution levels, cofactors and sensitization to other plant food allergens may also be involved. SUMMARY: While the majority of those with PFS will continue to experience mild symptoms, all individuals should be properly advised regarding the dangers of concentrated or unusual forms of plant food allergens such as smoothies, juices, soy/nut milks and nutritional supplements. Further well characterized studies are needed to determine risk factors for severe reactions, and sensitization patterns to pollens and plant food allergens.

Frequency and clinical features of pollen-food syndrome in children.

BACKGROUND: Pollen-food syndrome (PFS) is an allergic reaction to fresh fruits, vegetables and/or nuts that can occur in patients who are allergic to pollen. The prevalence of PFS in children is not clearly known. OBJECTIVE: The objective of this study was to determine the frequency and clinical features of PFS in pediatric patients with pollen-induced allergic rhinitis (AR). METHOD: This study was conducted in the pediatric allergy outpatient clinic of our hospital. Pollen-induced seasonal AR patients who were evaluated for any symptoms appearing after consuming any fresh fruits and vegetables. RESULTS: Six hundred and seventy-two pollen-sensitized patients were included in this study. The symptoms related to PFS were reported in 22 (3.3%) patients. The median age of the patients was 12.3 years and 59% (n=13) were female. Peach was the most common culprit (22%). There were isolated oropharyngeal symptoms in 20 (91%) patients and anaphylaxis in two (9%) patients with the suspected food. The multiple logistic regression analysis revealed that female gender, history of atopic dermatitis and allergic diseases in the family were the potential risk factors for PFS [Odds ratio 95%CI: 3.367 (1.344-8.435), 5.120 (1.935-13.550), 3.046 (1.239-7.492), respectively]. CONCLUSION: PFS can be seen in children who are followed up for pollen-induced AR. The symptoms of PFS are usually mild and transient. However, comprehensive evaluation of patients is important since serious systemic reactions such as anaphylaxis can also be observed.

IgE antibody repertoire in nasal secretions of children and adults with seasonal allergic rhinitis: A molecular analysis.

BACKGROUND: There is growing interest both in testing IgE in nasal secretions (NS) and in molecular diagnosis of seasonal allergic rhinitis (SAR). Yet, the reliability of nasal IgE detection with the newest molecular assays has never been assessed in a large cohort of pollen allergic patients. OBJECTIVE: To investigate with microarray technology and compare the repertoires of specific IgE (sIgE) antibodies in NS and sera of a large population of children and adults with SAR. METHODS: Nasal secretions were collected with an absorbent device (Merocel 2000® , Medtronic) and a minimal dilution procedure from 90 children and 71 adults with SAR. Total IgE (tIgE) (ImmunoCAP, Thermo Fisher Scientific (TFS)) and sIgE antibodies against 112 allergen molecules (ISAC-112, TFS) were measured in NS and serum. RESULTS: Nasal sIgE was detectable in 68.3% of the patients. The detected nasal sIgE antibodies recognized airborne (88%), vegetable (10%), and animal food or other (<1%) allergen molecules. The prevalence and average levels of sIgE in NS and serum were highly interrelated at population level. A positive nasal sIgE antibody to a given molecule predicted the detection of the same antibody in the patient's serum with a specificity of 99.7% and a sensitivity of 40%. CONCLUSIONS: The concentration of sIgE is much lower in nasal secretions than in the serum. sIgE assays with very high analytical sensitivity and sampling methods with minimal dilution will be therefore needed to validate nasal secretions as alternative to serum in testing the sIgE repertoire.

[Clinical symptoms of the allergic rhinitis and coexisting cross reactions in patients treated with the birch and/or grasses allergens against a background of the pollen exposure].

During specific immunotherapy (SIT) it is recommended to monitor the patient symptoms in relation to the exposure of allergen which the patient is treated. The aim of the study was to analyze the clinical symptoms of allergic rhinitis (AR) and cross reactivity in patients undergoing specific immunotherapy using pollen allergens (SIT) (birch and/or grasses) against the pollen exposure in 2014-2016. The study group, consisted of patients with pollen allergy, treated by SIT with birch and grasses allergens, who showed oral allergy symptoms. Patients of the control group were sensitive to birch and/or grasses allergens and they were not treated with SIT. The analyses were based on the results of questionnaires and patient symptom diaries. Timing of the pollen seasons of birch and grasses were similar, however the significantly higher concentration of birch pollen was found in 2014 and 2016, comparing to 2015. The strongest relationship between the pollen concentration and symptoms severity was revealed in the study group in patients desensitized by combined vaccine (birch/grasses), while in the control group, in patients sensitive to both taxa. In 35.3% of patients in the study group, a significant decrease in symptoms after foods was found, especially in patients desensitized with mixed vaccine (birch, grasses) after consumption of vegetables and in patients desensitized with grasses allergens after the fruits and nuts. SIT has a significant impact on the symptoms score reduction, which could be modified by the changeable seasonal pollen exposure.

Fruit and vegetable allergy.

Fruit and vegetable allergies are the most prevalent food allergies in adolescents and adults. The identification of the allergens involved and the elucidation of their intrinsic properties and cross-reactivity patterns has helped in the understanding of the mechanisms of sensitisation and how the allergen profiles determine the different phenotypes. The most frequent yet contrasting fruit and vegetable allergies are pollen-food syndrome (PFS) and lipid transfer protein (LTP) syndrome. In PFS, fruit and vegetable allergies result from a primary sensitisation to labile pollen allergens, such as Bet v 1 or profilin, and the resulting phenotype is mainly mild, consisting of local oropharyngeal reactions. In contrast, LTP syndrome results from a primary sensitisation to LTPs, which are stable plant food allergens, inducing frequent systemic reactions and even anaphylaxis. Although much less prevalent, severe fruit allergies may be associated with latex (latex-fruit syndrome). Molecular diagnosis is essential in guiding the management and risk assessment of these patients. Current management strategies comprise avoidance and rescue medication, including adrenaline, for severe LTP allergies. Specific immunotherapy with pollen is not indicated to treat pollen-food syndrome, but sublingual immunotherapy with LTPs seems to be a promising therapy for LTP syndrome.

Oral allergy syndrome (pollen-food allergy syndrome).

Oral allergy syndrome (OAS) or pollen-food allergy syndrome (PFS) is a hypersensitivity reaction to plant-based foods, manifesting most commonly with pruritus of the lips, tongue, and mouth. Unlike simple food allergy, OAS requires prior sensitization to a cross-reacting inhalant allergen rather than direct sensitization to a specific food protein. In this review, we summarize the clinical features and pathophysiology of OAS and provide an overview of known pollen-food associations.

Prevention of food allergy in the real life.

The prevalence of food allergy has increased exponentially in the last decade and is fast becoming the second wave of the allergy epidemic. Secondary prevention methods such as treatment of accidental exposures and immunotherapy are still fraught with difficulties and unanticipated adverse events still occur. The future of food allergy management may lie in primary prevention, of which practical strategies and current evidence are summarized in this review. No maternal dietary restrictions are required during pregnancy and lactation. High risk infants should be exclusively breastfed for at least 4 to 6 months with early introduction of complementary solid foods. Hydrolyzed formulas may be used for high risk infants who are not exclusively breastfed. A healthy balanced diet inclusive of fresh fruits, vegetables and vitamins may play an important role in prevention of allergies and has myriad advantages to general health and well-being. There remains a need for large scale randomized controlled trials for all other nutritional interventions in the hope that more can be done for the primary prevention of allergies in the future.

Diagnostic usefulness of component-resolved diagnosis by skin prick tests and specific IgE to single allergen components in children with allergy to fruits and vegetables.

INTRODUCTION: The accurate identification of sensitizing proteins in patients allergic to plant-derived foods is extremely important, allowing a correct dietary advice. We aimed to evaluate the diagnostic usefulness of skin prick tests (SPT) and specific IgE (sIgE) with single molecular allergen components in children with allergy to fruits and vegetables. METHODS: Twenty children underwent SPT with a palm profilin (Pho d 2, 50 µg/mL); a Mal d 1-enriched apple extract (2 µg/mL) (PR-10 allergen); and a peach Lipid Transfer Protein (LTP) (Pru p 3, 30 µg/mL). Detection of sIgE to rBet v 1, rBet v 2, Phl p 12 and Pru p 3 was also measured. RESULTS: Allergy to multiple fruits and vegetables was observed in 11 (55%) children. Sensitization by SPT to Pho d 2, Mal d 1, and Pru p 3 occurred in 5, 7, and 8 cases, respectively. LTP sensitization appeared to be associated with peach allergy but not with severe reactions, and profilins sensitization to melon and tomato allergy. Kiwi sensitization (12 cases), the plant-derived food that caused more allergic reactions, seemed mostly species-specific. The concordance of SPT extracts and sIgE to the corresponding pan-allergens was high for profilins (k=0.857) and LTP (k=0.706), while for PR-10 allergens it was absent (k=0.079). CONCLUSIONS: Pan-allergen sensitization in children with allergy to fruits and vegetables was common and often multiple. There was no association of severe reactions to LTP sensitization. The introduction of routine SPT to pan-allergens can be a simple and feasible way of improving diagnostic and therapeutic efficacy.

Novel approaches to food allergy.

Food allergies have increased in recent decades. However, they cannot be effectively treated by the current management, which is limited to the identification and avoidance of foods that induce allergies and to the use of medicines for symptoms relief. To meet the medical need of prevention and cure of food allergies, several therapeutic strategies are under investigation. Some newly developed biologics such as anti-IgE antibody and anti-interleukin (IL)-5 antibody directed against significant molecules in the allergic process have shown their potential for the treatment of food allergies. Allergen-specific immunotherapy is the therapy that induces immune tolerance and may reduce the need for conventional medication, severity of allergic symptoms and eliminate hypersensitivity. In this article, clinical studies of immunotherapy via subcutaneous, oral, sublingual, and epicutaneous routes are extensively reviewed for their safety and effectiveness on various food allergies. In addition, to reduce the risk of anaphylaxis and increase toleragenic immunity, many studies are focusing on the modification of traditional allergens used for immunotherapy. Moreover, a Chinese herbal formulation with potential anti-allergic effects is being evaluated for its efficacy in patients with peanut allergy. Although more studies are needed, accumulated data of current studies represent compelling evidence of curative effects of some strategies and give a hope that food allergies are likely to be successfully treated in the future.

The biochemical basis and clinical evidence of food allergy due to lipid transfer proteins: a comprehensive review.

Plant lipid transfer proteins (LTPs) are ubiquitous proteins that are found in divergent plant species. Although the exact function of LTPs is not fully understood, LTPs are conserved across a broad range of plant species. Because LTPs share structural features, there is an increased probability for significant allergic cross-reactivity. The molecular features of LTPs also decrease the probability of degradation due to cooking or digestion, thereby increasing the probability of systemic absorption and severe allergic reactions. LTP allergy, unlike other forms of anaphylaxis, tends to occur more frequently in areas of lower latitude. The geographic distribution of LTP allergy, along with evidence of increased sensitization after respiratory exposure, has led to the hypothesis that LTP-related food allergy may be secondary to sensitization via the respiratory route. Clinical reactions associated with LTPs have broad clinical phenotypes and can be severe in nature. Life-threatening clinical reactions have been associated with ingestion of a multitude of plant products. Component-resolved diagnosis has played a significant role in research applications for LTP allergy. In the future, component-resolved diagnosis may play a significant role in day-to-day clinical care. Also, quantitative analysis of LTPs in foodstuffs may allow for the identification and/or production of low-LTP foods, thereby decreasing the risk to patients with LTP allergy. Furthermore, sublingual immunotherapy may provide a therapeutic option for patients with LTP allergy.

Food allergy in Africa: myth or reality?

Food allergy has been traditionally perceived as being rare in Africa. However, the prevalence of other allergic manifestations such as asthma and atopic dermatitis continue to rise in the higher-income African countries. Since the food allergy epidemic in westernized countries has lagged behind that of allergic respiratory conditions, we hypothesize that food allergy is increasing in Africa. This article systematically reviews the evidence for food allergy in Africa, obtained through searching databases including PubMed, Medline, MD Consult, and scholarly Google. Articles are divided into categories based on strength of methodological diagnosis of food allergy. Information was found for 11 African countries: Botswana, Democratic Republic of Congo, Ghana, Kenya, Morocco, Mozambique, Nigeria, South Africa, Tanzania, Tunisia, and Zimbabwe. Most studies reflect sensitization to food or self-reported symptoms. However, a few studies had more stringent diagnostic testing that is convincing for food allergy, mostly conducted in South Africa. Apart from the foods that commonly cause allergy in westernized countries, other regionally significant or novel food allergens may include pineapple (Ghana), okra (Nigeria), and mopane worm (Botswana). Food allergy is definitely an emerging disease in Africa and resources need to be diverted to study, diagnose, treat, and prevent this important disease.

Cross allergic reactions in infants and toddlers with atopic dermatitis.

PURPOSE: Prevalence and clinical significance of cross sensitization in children up to 3 years old, diagnosed with atopic dermatitis. MATERIAL AND METHOD: The retrospective study included 69 children up to 3 years old with atopic dermatitis. Allergological diagnostics was performed based on skin tests, determination of total IgE concentration and allergen-specific IgE. RESULTS: Cross sensitization was found in 26% of children. Other patients were qualified to the control group. The sensitization to trees pollen and fruits as well as grass pollen and vegetables were the most frequent types of cross allergy. The patient's family history was positive with regard to atopy in 72% of children from the study group vs. 31% of children from the control group. The statistically higher prevalence of allergic rhinitis and bronchial asthma as well as co-existence of sensitization to house dust mite and animal dander were revealed in the study group. The total concentration of IgE, eosinophilia and SCORAD values were statistically higher in the study group. Children with cross sensitization required systemic steroid therapy more frequently. CONCLUSION: In children up to 3 years with atopic dermatitis and sensitization to plant pollen, the role of a pollen-food allergy syndrome must be taken into account in the pathogenesis of the disease. In children with cross sensitization, the course of atopic dermatitis is more severe; the symptoms from the respiratory and digestive system co-exist. The positive family history is a factor, predisposing to the development of cross sensitization in infants and toddlers.

[Questionnaire about the intake of and hypersensitivity to fruits, vegetables and nuts including birch pollen related foods].

BACKGROUND: In Hokkaido and Scandinavia, birch pollen allergic persons are common and they often report oral and pharyngeal hypersensitivity to fruits and vegetables (oral allergy syndrome, OAS), because of immunological cross-reactivity. In Scandinavia, nuts as well as Rosaceae fruits such as apples were the foods most often reported to elicit symptoms. On the other hand, nuts are minor foods causing hypersensitivity in Japan. Even in Japan, regional differences of foods causing hypersensitivity have been reported, which may be related to the regional differences of elementary habit and pollen dispersion. In the present study, we evaluated the intake history of the foods and the frequency of food hypersensitivity in adults from the general population. METHODS: Three hundreds and thirty nine subjects (20-67 years old) took part in the study. With a questionnaire survey, we asked them about their intake history and hypersensitive symptoms for 33 kinds of fruit, vegetables, and nuts. RESULTS: 30% of subjects had eaten Brazil nuts, 80% had eaten pomegranates, and 81% had eaten hazelnuts. And over 95% of subjects had eaten the other 30 foods. Those who had lived in Hokkaido for more than 20 years had a higher frequency of plum consumption than the others. Those who had lived in Hokkaido for more than 20 years had a lower frequency of loquat, fig and pomegranate consumption than the others. Food hypersensitivity was found in 52 subjects (15.3%). The most common symptom was OAS (46 subjects, 13.6%), and foods most frequently causing OAS were peach (21 subjects, 6.2%), cherry (19 subjects, 5.6%) and apple (17 subjects, 5.0%). 26 subjects (7.7%) reported OAS to Rosaceae fruits. The ratio of having OAS to consuming Rosaceae fruits was 11.0% in the group who had lived in Hokkaido for more than 20 years, which was higher than the group who has lived in Hokkaido for less than 20 years. The intake history of hazelnuts and Brazil nuts was very low, with a correspondingly low frequency of food hypersensitivity associated with these nuts. CONCLUSION: The frequency of intake and hypersensitivity of some foods differ among different regions.